Sets the socket type to be used for the next call to
openlog() or syslog() and returns TRUE on success,
undef on failure.

A value of 'unix' will connect to the UNIX domain socket returned by the
_PATH_LOG macro (if you system defines it) in syslog.h. A value of
'inet' will connect to an INET socket returned by getservbyname(). If
_PATH_LOG is unavailable or if getservbyname() fails, returns undef. Any
other value croaks.